Mini Subwoofer

[EWorkshop1708]

I'm wanting to build a mini portable sound system for work, home, or whereever. I want it to have good sound for the size, and most small speaker lack in bass. I'll be using a 4 channel BTL Car Radio IC to drive the front speakers and sub.

I found this small sub at Parts Express:
http://www.partsexpress.com/pe/showd...number=264-831

The idea, was to use a pair of rare 2 1/4" 5W drivers for L & R and use the sub inside the box for bottom end.

Anyone here use this sub before. I'm not going for really loud output, but the low 82db efficiency has my attention, and I'm wondering if it will still be louder than an avg boombox.

Also, are there any other small subs out there that may do as well? I'd rather have a 2 ohm sub if I can find one.

[EWorkshop1708]

For more info, I'll be giving the sub 16W RMS @ 4 ohm

Front channels 8W RMS @ 8 ohm per channel. Should be 32W RMS total with 2 speakers and subwoofer. Also will have 14.4V of batteries inside the unit for portable use.

[y8s]

use 4? that'd raise your sensitivity

[EWorkshop1708]

Originally posted by y8s
use 4? that'd raise your sensitivity

And also won't be so mini anymore

I was thinking about two of them, but I'm really wanting this to be small, so I want to stick with one sub. I want the box to be 7 or 8 inch cube max, just big enough for a portable FM/CD player to fit on top.

The sub has over 9mm of Xmax, so I'm thinking even if it's not loud, it should still add some much needed bass. I've never seen a 5 inch sub like that before.

[CarlosT]

You're gonna make this a sealed box then? Those are pretty small dimensions...your target cube box...

[Cal Weldon]

Originally posted by EWorkshop1708
and I'm wondering if it will still be louder than an avg boombox.

Not as loud but the potential to go deeper and sound better. I use it's big brother the W6-1139 and am surprised how well it handles the lows.

[EWorkshop1708]

That's cool. Glad you have had good experience with their small subs.

I don't need it super loud, just good sound. It will mainly be used at work for portable sound, or at home for sound at my spare computer. Or to have sound in one of my cars that has no stereo. I'm hoping this type of sub will sound good. I want at least a good 50-60hz bass note from this thing. Lower is a bonus, but not necessary.

That sub is rated close to 0.25 cu ft, so my small box should be fine. I want to make sealed on the backside of the woofer, with a small vented chamber on the front side, kind of like a bandpass, but open, for the bass to come out of. This is to protect the woofer, and try to get some more output. Feel free to comment on the box needed for a small subwoofer.

I want to stick with the 14.4V NiCd battery, to get good output. I'll just have a 12V 4A (17V unreg) transformer providing the charge for the battery, and to provide mains power for the amp. I'll use the batteries like big filter caps for the DC power coming in, and it will keep the batteries slowly charged and topped off at the right volts.

The Car Radio the IC amp come from had max power rating at 4 ohms a channel of 40W x 4 @ 14.4V (16W RMS x 4) So using 2 8 ohm speakers (8WRMS x 2) and a single 4 ohm subwoofer (16WRMS) should use about 1/2 the total wattage of the IC (32W RMS) with IMO should still be pretty loud, but not kill my batteries.

IC HA13158A is the amplifier.

[DaveCan]

This small sub may be a better choice http://www.edesignaudio.com/product_...products_id=33
Dave

[sdclc126]

EWorkshop1708 - for what it's worth, I have a pair of W5-1138SMs in my car, a Ford Focus 3-door. I put them on the rear two channels in the factory locations.

The efficiency is an issue, so I've adjusted the amp gain, but I can say that they are very clean and accurate - I listen to a lot of classical music and they have no trouble with pipe organ and bass drum, etc. - they don't seem to miss anything down in the low end. I may put an 8" third sub in my trunk area (5-channel amp) to see what difference it makes, just as an experiment.

I wouldn't recommend them for high SPLs with things like rap music and synthesized base, but for small systems and limited space applications they are quite appropriate.

[sreten]

Originally posted by EWorkshop1708


That sub is rated close to 0.25 cu ft, so my small box should be fine.
I want to make sealed on the backside of the woofer, with a small vented chamber on the front side, kind of like a bandpass, but open, for the bass to come out of. This is to protect the woofer, and try to get some more output. Feel free to comment on the box needed for a small subwoofer.

Hi,

An 8" cube of 1/2" stock is 0.2 cuft Q=0.75, 3/4" 0.16cuft Q=0.8.
Bass in boombox context is very good, f6 at 50Hz, f10 at 40Hz.

Given this I cannot see why the volume penalty of a bandpass
arrangement, especially as the sub might need to go quite high
presuming that the 2 1/4" drivers will not do low.

/sreten.